n8n

n8n does what Zapier does, drawn as a diagram: boxes for each step, lines between them, AI steps wherever you want them. The difference that matters is that you can run it on a small server you already pay for, with no per-task charge.

Where it fits

You have outgrown the free tier of the easy tools, you have a server or do not mind getting one, and your workflows have grown branches: if the email is from a client do this, otherwise that, and loop over the attachments. That is where a drawn workflow beats a list of boxes.

Where it does not

If you want it working this afternoon with nothing to install, Zapier is easier. If the job is one prompt on a schedule, the AI apps do that themselves. And if you would rather describe a goal than draw the steps, that is an agent, not a workflow tool; mine replaced most of what I would have drawn here.

Honest limitations

I have not run it in anger, so read this as orientation. Self-hosting means you own the updates, the backups and the three-in-the-morning restart. The hosted version removes that and brings the bill back. There is a learning curve that Zapier does not have.

Next step

If you already have a server from the Hermes guide, it is a reasonable thing to add to it. If you do not, start with the easy tool and see whether you even want the diagram.